Second Quarter 2018
INL Quarterly Site Environmental Report

Appendix B
SUMMARY OF MDCs AND DCSs

Table B-1. Summary of Approximate Minimum Detectable Concentrations for Radiological Analyses Performed during Second Quarter 2018

Sample Type

Analysis

Approximate Minimum Detectable Concentrationa(MDC)

Derived Concentration Standardb(DCS)

Air
(particulate filter)e

Gross alphac

5.8 x 10-16 µCi/mL

3.4 x 10-14 µCi/mL

Gross betad

1.4 x 10-15 µCi/mL

2.5 x 10-11 µCi/mL

137Cs

8.7 x 10-17 µCi/mL

9.8 x 10-11 µCi/mL

90Sr

1.9 x 10-17 µCi/mL

2.5 x 10-11 µCi/mL

241Am

4.6 x 10-18 µCi/mL

4.1 x 10-14 µCi/mL

238Pu

7.8 x 10-18 µCi/mL

3.7 x 10-14 µCi/mL

239/240Pu

8.7 x 10-18 µCi/mL

3.4 x 10-14 µCi/mL

Air (charcoal cartridge)e

131I

5.2 x 10-16 µCi/mL

2.3 x 10-19 µCi/mL

Air (atmospheric moisture)e

H3

87.2 pCi/Lwater

5.6 x 10-13 µCi/mLair

2.1 x 10-7 µCi/mLair

Air (precipitation)

H3

85.5 pCi/L

1.9 x 10-3 µCi/mL

Drinking Water/Surface Water

Gross Alpha

1.09 pCi/L

1.7 x 10-7 µCi/mL

Gross Beta

1.31 pCi/L

1.1 x 10-6 µCi/mL

3H

86.7 pCi/L

1.9 x 10-3 µCi/mL

137Cs(BLR)

0.91 pCi/L

--g

Milk

3H

85.8 pCi/L

--

90Sr

0.075 pCi/L

--

131I

0.5 pCi/L

--

137Cs

1.0 pCi/L

--

Alfalfa

137Cs

1.81 pCi/kg

--

90Sr

79.7 pCi/kg

--

The MDC is an estimate of the concentration of radioactivity in a given sample type that can be identified with a 95 percent level of confidence. MDCs are calculated and reported by the laboratories based on actual ESER sample results following analysis.

DCSs, set by the DOE, represent reference values for radiation exposure. They are based on a radiation dose of 100 mrem/yr for exposure through a particular exposure mode such as direct exposure, inhalation, or ingestion of water.

Based on the most restrictive human-made alpha emitter (239Pu).

Based on the most restrictive human-made beta emitter (90Sr).

The approximate MDC is based on an average filtered air volume (pressure corrected) of 445 m3/week.

Radiation in Our World

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Radiation Exposure and Dose

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